Brine is a combination of water and common NaCl salt, in making cheese other parameters are acidity and calcium levels of brine.

Salt Amount

Cold household fridge stored saturated water based brine and water based brine ripening feta in plastic containers.

Many cheese making procedures, when using brine for salting cheese, call for brine between 18 & 23% salt. This is because:

The range of brine resistant spoilage and pathogen type microorganisms that can survive in brine increases significantly at less than 16% salt and 18% provides a safety margin. Weak brines are notorious sources of contamination and thus if used, should be disposed of after using and not re-used. Weak brines also result in less moisture loss from the cheese surface, resulting in several possible defects:

As less salt, the body of the cheese will be higher water content and thus weaker and softer than desired.

Initially soft/swollen cheese from less brine inhibition and a slimy, greasy, or “melting” surface of the newly formed cheese.

As less salt in the cheese, the acidity development will be less retarded, resulting in higher acidity (lower pH) will favour the growth of spoilage organisms. For aged type cheeses you can get sticky and discoloured rind patches, varying from straw to bright orange, red or brown. Also, the surface will be prone to show growths of the black or grey mucor molds (poille de chat).

Brines above 23% salt increases the risk that moisture will be lost too rapidly from the surface of the cheese. This can result in a very dehydrated surface layer which may hinder or reduce the further uptake of salt into the body of the cheese to reach the correct % salt in cheese, depending on cheese type.

However, some home type cheese making recipes call for brining with saturated (typically 26% salt at 60°F/15°C) brines. This is because saturated brines:

Are easier to make accurately and maintain than lower % salt brines.

As easier to make accurately they provide an easy standard against which future cheese making batches can be measured.

Brine Additives

Four pound Gouda brining in saturated water based brine in stainless steel stockpot.

Freshly made brines, will when first used for brining a cheese, exhibit cat ion exchange whereby the calcium and hydrogen ions in the cheese surface will transfer to the brine until the brine and cheese reaches equilibrium. This transfer will cause the casein in the cheese surface to absorb water and swell resulting in a soft slimy surface layer that in aged cheeses leads to rind rot during aging. To mitigate this transfer:

Acidify the new brine to a pH of ~5.0, or roughly the same pH as the cheese. This can be done by several methods listed from optimal to least preferable:

Using drained whey instead of water for base of brine.

Adding Citric Acid to water.

Adding Acetic Acid (vinegar) to water.

Add food grade CaCl2 to the brine until reach 0.1%.

Brine Tank

Brine tanks should have the following properties:

Sturdy to avoid failure from the weight and pressure (if large tank) of dense brine fluid.

Be large enough for the brine plus the cheese(s) plus the cheese insertion or removal device (i.e. hand and arm or metal device) plus a free area for mini-waves when placing and removing cheese.

Made of a salt corrosive resistant material, such as plastic or high quality stainless steel. Note, most stainless steel stockpots are not of high enough quality steel to avoid corrosion and also often have easily corrodible aluminum rivets attaching handles.

In brines, % salt is a measure of the weight of salt divided by the weight of brine, i.e. if you dissolve 1 kg of salt in 5 liters of water, the brine will weigh 6 kg and you will have 1/6 = 16.7% salt brine.

Example American Units Calculation: Say you want to make 2 US gallons of 10% brine. Table below says 0.1111 pounds salt/US gallon of water for ~10% brine. Thus combine 2 US gallons water and 2 x 0.1111 = 0.2222 pounds salt and stir until dissolved.

When salt is dissolved in water, it makes the resulting volume of brine slightly bigger depending on the amount of salt. For example the above 16% brine examples will be about 5% larger volume that the original amount of water used.

A very fresh egg will float in a 20% salt solution and often used as very reliable method in home brine making.

Brine Making Table

The table below is at standard conditions of 60°F/15.6°C and only goes up to 26% as at 26.395% brine is fully saturated (at 60°F) and any additional salt will not dissolve.